1. Field of the Invention
The present invention is directed to a shock wave generator of the type used in extracorporeal lithotripsy treatment of a patient, and in particular to such a shock wave source having a housing terminating in a flexible sack which covers the exit opening for the shock waves, the sack limiting a coupling volume filled with a coupling fluid.
2. Description of the Prior Art
A shock wave generator in the form of a shock wave tube having an exit opening for the shock waves which is covered by a flexible sack, which is disposed against the body surface of a patient to be treated, is disclosed in German AS No. 33 28 051, corresponding to U.S. Pat. No. 4,674,505. The flexible sack limits a volume which is filled with a coupling fluid to assist coupling of the shock waves to the body of the patient. In this known shock wave generator, the shock wave source is mounted stationary with respect to the housing. The entire shock wave generator must therefore be displaced to set, or reset, the focus. If, for example, the shock wave generator is acoustically applied to the surface of the patient via the flexible sack and a gel disc, and if a displacement of the focus is thereafter required, a decoupling of the shock wave generator and a repeated acoustic application must be undertaken. The examining personnel are burdened as a result, and the treatment is prolonged.